1. Field of the Invention
The present invention relates to dual-standby portable terminals. More particularly, the present invention relates to an apparatus and method for removing interference in a dual-standby portable terminal, thereby improving received signal sensitivity of the dual-standby portable terminal.
2. Description of the Related Art
As portable terminals have become widely used, manufacturers have developed portable terminals with an increasing amount of functions. In recent years, multi-mode portable terminals have appeared on the market, which can use two or more wireless communication networks.
Portable terminals that support only one type of wireless communication network can perform communication within only a corresponding wireless communication network service area. The multi-mode portable terminals, however, can perform communication within at least two or more wireless communication network service areas. Dual mode portable terminals can support a Code Division Multiple Access (CDMA) network and a Global System for Mobile communication (GSM) network, so that they can perform communication within both CDMA and GSM network service areas. The dual mode portable terminals can be more widely used than the single mode portable terminals.
However, since the conventional multi-mode portable terminals switch between networks in such a way that they are booted, enter an idle mode, and then perform communication by operating their menu, they are complicated to operate and require a lot of time to switch their modes.
To address the above-mentioned problems a dual standby portable terminal has been proposed, which can simultaneously support two networks, for example, a CDMA network and a GSM network.
A Low Noise Amplifier (LNA) is installed in a receiving unit of respective communication modules in a dual standby portable terminal and repeatedly and periodically operates, according to the slot index cycle, as power is supplied on and off.
However, the LNA requires a certain period of time from when it receives power until it is stabilized. During this period of time, transmission power, generated as any one of the communication modules enters a communication mode, may be applied to an LNA of the other communication module in a reception standby mode.